The Osaka-Lake Biwa Marathon is a major autumn road race held in Osaka, Japan, featuring a certified 42.195 km course for elite men, non-elite men, and non-elite women. Launched in 2011, the race saw over 27,000 starters in its inaugural edition and has become a staple on Japan’s urban marathon calendar. Since 2019, the course has started and finished near Osaka Castle Park, offering runners a scenic yet efficient urban loop. Following a 2022 organizational shift, the elite men’s race was merged into the historic Lake Biwa Marathon, while the Osaka event continues to host a large-scale mass participation race and an 8.8 km Challenge Run. The course is fast and well-supported, combining big-race logistics with a central city location.